Abstract
After oral administration of 14C-labelled $N^G$-mono[methyl-14C]-L-arginine into rats, 38.2 % and 14.7 % of the administered radioactivity bad been recovered in the urine and stool during 10 days. In the urine, 59.4 % of the radioactivity was recovered in the first 24-hours and used for the indentification of the formation of methylamine. The strong cation-exchange resin column chromatography showed 6.3 %, 7.4 %, 4.9 %, and 81.5 % of the distributions of radioactivity of the neutral, monomethylamine, basic, and uneluted portions, respectively. The radioactivity of monomethylamine portion reeluted into the column chromatography was 39.5 %. The radioactivities corresponding monomethylamine in the column chromatography, thin-layer chromatography, and thin-layer electrophoresis were 39.5 %, 37.3 %, and 28.8 % of the recovered radioactivity, respectively.